Did you know that dolphins use tools, and look adorable while doing so?
Bottlenose dolphins in Australia's Shark Bay like to snack on seafloor-dwelling fish (like sandperch), a food choice that presents two problems. First, these fish lack swimbladders and therefore cannot be echolocated effectively; second, the substrate they inhabit is scattered with sharp rocks and shells, which obscure the fish and conspire to injure a dolphin's nose. One group of dolphins came up with a clever way to enjoy their benthic prey: they harvest sponges and wear them on their faces. The sponge protects the dolphin's rostrum while it digs around in the seafloor, until it runs into a fish and scares it out of the ground to be eaten. After about an hour, when the sponges become too worn down to serve as a shield, the dolphins replace them with fresh ones. Furthermore, the dolphins pass the knowledge of sponging on from generation to generation. Read more details in this scientific paper.
Patterson EM, Mann J (2011) The Ecological Conditions That Favor Tool Use and Innovation in Wild Bottlenose Dolphins (Tursiops sp.). PLoS ONE 6(7): e22243. doi:10.1371/journal.pone.0022243